[modeleng] Re: sprockets
- From: "Richard Gays" <Richard.Gays@xxxxxxxxxxxx>
- To: <modeleng@xxxxxxxxxxxxx>
- Date: Mon, 30 Aug 2004 12:09:27 +0100
Hi Terry,
In imperial figures, 240 holes on 19.105" pcd will be exactly .250"
apart. This is only a 486.41 mm pcd, but you did say approx 500 and 240
holes at 1.500 degrees sounds a lot easier to me, not that I fancy having to
drill them.
----- Original Message -----
From: "Terry Lane" <tel@xxxxxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Monday, August 30, 2004 11:45 AM
Subject: [modeleng] Re: sprockets
> Thanks Rich - now where did I put that 247 tooth gear wheel to index it
> with?
>
>
> > Hi there Terry,
> >
> > I'd suggest the following (hoping my maths is correct):-
> >
> > Guess the number of holes - a good estimate would be to say that the
> > circumference of your 500mm sprocket is about pi*500mm, which is 1571mm,
> > and your pitch is 1/4"=6.35mm, which goes into the circumference about
247
> > times.
> >
> > Divide 360 degrees with that number - leaving 1.4575 degrees.
> >
> > Now draw out a right angled triangle in front of you, with one angle
very
> > small.
> >
> > Assume that this small angle is half of the 1.4575 degrees (0.7287
> > degrees), and that the side opposite this angle is half of your pitch
> > (1/8"=3.175mm).
> >
> > The hypotenuse of the triangle should not be the RADIUS that you should
> > form the holes on for your sprocket for 495 teeth:-
> >
> > hole radius= 3.175mm/ sin 0.7287degrees = 249.633mm
> >
> > giving a diameter for your holes to lie on of 499.267mm.
> >
> > This doesn't allow for any clearance between the chain rollers and the
> > sprocket though.
> >
> > Hope this is of some use.
> >
> >
> > Yours,
> >
> >
> > Rich.
> > PS 247 HOLES!!! OUCH!
> >
> > On Mon, 30 Aug 2004, Terry Lane wrote:
> >
> > > I'm sure the info is somewhere but - have any of you got a quick way
of
> > > calculating sprocket cutting. I got a job here that calls for a
sprocket
> > > aprox 500mm diameter to drive 1/4" pitch chain. Now OK - the teeth
gotta
> be
> > > one pitch apart, & the holes gotta be pin dia.+?, but how do I arrive
at
> a
> > > pitch circle for the ring of holes?
> > >
> > >
> > > MODEL ENGINEERING DISCUSSION LIST.
> > >
> > > To UNSUBSCRIBE from this list, send a blank email to,
> > > modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the
> subject line.
> > >
> > >
> >
> > MODEL ENGINEERING DISCUSSION LIST.
> >
> > To UNSUBSCRIBE from this list, send a blank email to,
> > modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the
subject
> line.
> >
>
> MODEL ENGINEERING DISCUSSION LIST.
>
> To UNSUBSCRIBE from this list, send a blank email to,
> modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject
line.
MODEL ENGINEERING DISCUSSION LIST.
To UNSUBSCRIBE from this list, send a blank email to,
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.
Other related posts:
